The mysterious mission is to decrypt the hidden infomation from the statement of problems.

Here is how to solve it in detail:

Part of input in the example input of the problem H is obviously three of four pieces of an QR-code:

11
11111110111
10000010010
10111010011
10111010011
10111010001
10000010000
11111110101
00000000111
11011010011
10010101100
11101010100
11
11011111110
10010000010
00010111010
10010111010
01010111010
11010000010
01011111110
11000000000
01010000010
01000111100
00000001010
11
11010101001
11001010100
00000000110
11111110010
10000010010
10111010110
10111010111
10111010010
10000010110
11111110100
00000000000

And we can also find that it has a missing part after arrangement:

██████████████  ██████████  ██████████████
██          ██    ██  ██    ██          ██
██  ██████  ██    ████      ██  ██████  ██
██  ██████  ██    ██████    ██  ██████  ██
██  ██████  ██      ██  ██  ██  ██████  ██
██          ██        ████  ██          ██
██████████████  ██  ██  ██  ██████████████
                ██████████
████  ████  ██    ████  ██  ██          ██
██    ██  ██  ████      ██      ████████
██████  ██  ██  ██                  ██  ██
████  ██  ██  ██    ██
████    ██  ██  ██
                ████
██████████████    ██
██          ██    ██
██  ██████  ██  ████
██  ██████  ██  ██████
██  ██████  ██    ██
██          ██  ████
██████████████  ██

The next task is that how to find the missing part.

The last input of H look like a charactor 'C', so we can turn to the problem C to find more information about it.

In the last example input of C, we can find a array with length of 11, which is seemed to be the missing part of our QRcode. Coding to turn the array to the binary representation and filling the QRcode with that result, we can get a mysterious URL after scanning the the completed QRcode.

678 201 340 444 453 922 128 987 127 752 0

void solve() {
    int n;
    std::cin >> n;
    while (n--) {
        // std::string s;
        int s;
        std::cin >> s;
        
        for (auto c : std::bitset<11>(s).to_string()) {
            std::cout << (c == '1' ? "██" : "  ");
        }

        std::cout << "\n";
    }
}

http://u5a.cn/JDtn0

However, it just get expired in this pastebin website, so we could never get the hidden information that the author want to pass. (which is sad, tbh)